This invention relates to vehicles having expandable room sections, and more particularly to a slide out assembly actuating mechanism and method of operation for use in vehicles, wherein the slide out assembly includes two or more fluid actuators for moving a slide out section between an extended and retracted position.
In order to increase the available interior space of recreational vehicles or trailers, it is known to provide a raised platform slide out section as part of the structure of the vehicle or trailer. The slide out section includes a raised platform, usable as seating, a sleeping platform, and the like, which is enclosed on all but one side. During transit, the slide out section is retracted and stored in the interior of the vehicle or trailer, with the exterior wall of the slide out section approximately flush with the exterior of the vehicle or trailer. To use the slide out section, the vehicle is first parked and leveled. The slide out room section is then slid outward from the vehicle to an extended position, increasing the interior space of the vehicle.
In prior art constructions, the slide out room section is moved between the extended and retracted position by an actuating mechanism driven by an electric motor, such as a rack and pinion system. The rack is typically fixed to the slide out section and a rotatably driven pinion is fixed to the vehicle body. These prior art constructions are adequate for many applications, however, they can be inefficient and are noisy.
Another known actuating mechanism incorporates hydraulic actuators that are actuated to extend and retract the slide out section. In slide out actuating mechanisms including two or more hydraulic or pneumatic actuators, fluid is pumped into each actuator at the same rate in order to extend the actuator rams together. Forces exerted on the slide out, such as by friction, an obstruction, and the like, can increase the pressure in one of the cylinders and reduce the flow of fluid into that cylinder which causes the ram of the one actuator to be extended less then the other actuators. This unbalanced condition can cause the slide out section to skew and become jammed. Therefore, a need exists for a vehicle slide out assembly actuating mechanism that synchronizes two or more fluid actuators to avoid skewing the slide out.